Spinal fusion surgeries, that is, the use of bone graft material to promote specific vertebrae to grow together into a solid and stable construct, are a common method of treating patients with severe back pain. For fusion to occur within the disc space, the surgeon must first remove the damaged disc material. During and/or or subsequent to the removal of the disc material, the empty space left between the upper and lower vertebrae can be distracted to relieve pressure from neural elements and to provide space for entry of surgical tools and/or implants. A bone graft, or interbody cage with bone, is then inserted into the empty disc space to promote bone growth from vertebral body to vertebral body. Recently, minimally invasive techniques have improved fusion procedures by causing less damage to tissue surrounding the damaged disc and allowing for faster recovery by the patient.
The initial step of removing the disc material from the intervertebral space is important because it facilitates fusion of the vertebrae. However, there are drawbacks with prior art instruments and techniques for removing a spinal disc. In a typical minimally invasive spinal fusion procedure, a small access port is formed in a patient that provides access to the disc. An instrument, such as a pituitary rongeur, is inserted through the access port and positioned between the vertebrae. The jaws of the pituitary rongeur are closed to engage a small piece of disc. The surgeon removes the instrument from the patient and scrapes off the small piece of disc material from the jaws. This process is repeated numerous times until the nucleus fibrosis and annulus of the disc are partly or completely removed. Because conventional instruments can only receive small pieces of disc material at a time, it can take up to 30 minutes for a surgeon to thoroughly remove the disc material. The small size of the access port can also make it difficult for a surgeon to manipulate an instrument and reach particular areas of the disc. Further, repeatedly inserting and removing sharp instruments from a patient can cause damage to soft tissue and nerves.
Accordingly, there remains a need for improved surgical instruments and methods for removing a spinal disc.